Our studies for the next year will continue to be concerned with the structure and function of proteoglycans and link proteins in cartilage of normal and mutant avian embryos. The mutant embryos are defective in their extracellular matrix macromolecules. Specifically these studies will deal with the characterization of intracellular proteoglycan core protein and link protein and their processing to functional extracellular matrix macromolecules. Our studies on the immunochemical properties of proteoglycans and link proteins will be continued. As an extension of the current immunochemical studies we will begin to elaborate monoclonal antibodies to both proteoglycans and link protein. These antibodies will be used as probes in the analysis of the structure of these macromolecules. Finally, we will enter in a collaboration with Dr. E. Buss of the Pennsylvania State University to study the proteoglycans in the cartilage of a chondrodystrophic turkey.